Scotopic and Photopic Conventional Visual Acuity and Hyperacuity - Binocular Summation.

Purpose: The purpose of this study was to determine and compare binocular summation (BiS) of conventional visual acuity (cVA) versus hyperacuity (hVA) for photopic and scotopic luminance conditions as a potential biomarker to assess the outcome of interventions on binocular function. Methods: Sixteen young adults (age range [years] = 21-31; 8 women; cVA logMAR < 0.0) participated in this study. The Freiburg Visual Acuity Test (FrACT) was used for VA testing and retested on another day. Both cVA and hVA were determined for dark grey optotypes on light grey background. Participants underwent 40 minutes of dark adaptation prior to scotopic VA testing. Binocular and monocular VA testing was performed. The eye with better VA over the 2 days of testing was selected, the BiS was quantified (binocular VA - better monocular VA) and repeated measures ANOVAs were performed. Results: Binocular VA exceeded monocular VA for all luminance conditions, VA-types, and sessions. We report BiS estimates for photopic and scotopic cVA and hVA, (logMAR BiS ± SEM [decimal BiS]): photopic = -0.01 ± 0.01 [1.03] and -0.06 ± 0.03 [1.15]; and scotopic = -0.05 ± 0.01 [1.12] and -0.11 ± 0.04 [1.28], respectively). Improvement for binocular vision estimates ranged from 0.01 to 0.11 logMAR. A repeated-measures ANOVA (RM ANOVA) did not reveal significant effects of LUMINANCE or VA TYPE on BiS, albeit a trend for strongest BiS for scotopic hVA (15% vs. 28%, photopic versus scotopic, respectively) and weakest for photopic cVA (3% vs. 12%, photopic versus scotopic conditions, respectively). Conclusions: Our results indicate that BiS of VA is relevant to scotopic and photopic hVA and cVA. It appears therefore a plausible candidate biomarker to assess the outcome of retinal therapies restoring rod or cone function on binocular vision. Translational Relevance: Binocular summation of visual acuity might serve as a clinical biomarker to monitor therapy outcome on binocular rod and cone-mediated vision.

Efficacy and adverse reactions of peripheral add multifocal soft contact lenses in childhood myopia: a meta-analysis.

OBJECTIVES: This study aims to compare the efficacy of peripheral add multifocal soft contact lenses (SCLs) (excluding bifocal SCLs) with single vision contact lenses or spectacles in controlling myopia progression. METHOD: A comprehensive literature search was conducted in the Pubmed, EMBASE, Web of Science, and Cochrane Library databases until October 2023. The literature was thoroughly screened based on predetermined eligibility criteria. Pooled odds ratios (ORs) were calculated for dichotomous data and weighted mean differences (WMD) for continuous data. RESULTS: A total of 11 articles comprising 787 participants were included in this meta-analysis. Our pooled results demonstrated that the peripheral add multifocal SCLs groups exhibited significantly reduced refraction progression (MD = 0.20; 95%CI, 0.14 ∼ 0.27; P<0.001) and less axial length elongation (MD=-0.08; 95%CI, -0.09∼-0.08; P<0.001) compared to the control group. There was no significant difference in high-contrast logMAR distance visual acuity between the two groups (MD = 0.01; 95%CI, -0.00 ∼ 0.02; P = 0.19). However, the group using single-vision lenses had better low-contrast logMAR distance visual acuity compared to those using peripheral add multifocal SCLs (MD = 0.06; 95%CI, 0.02 ∼ 0.10; P = 0.004). Data synthesis using a random-effects model indicated an incidence of contact lens-related adverse events of 0.065 (95%CI, 0.048 ∼ 0.083). CONCLUSIONS: The present meta-analysis signifies that peripheral defocus modifying contact lenses are effective in slowing down the progression of myopia and reducing axial elongation.

Evaluation of objective and subjective binocular ocular refraction with looking in type.

BACKGROUND: This study aimed to compare the results of the Chronos binocular/monocular refraction system, that measures objective and subjective ocular refraction in one unit, to objective findings obtained from a conventional autorefractometer and a conventional subjective ocular refraction using a trial-frame in real space. METHODS: Twenty-eight healthy volunteers (21.2 ± 1.5 years old) were included in this study. Objective ocular refraction was measured using two tests: the Chronos binocular/monocular refraction system under binocular conditions and a conventional autorefractometer under monocular conditions. Subjective ocular refraction was measured using three tests: Chronos binocular/monocular refraction system under binocular, monocular conditions, and trial-frame in the real space under monocular conditions. The measurement distance was set to 5.0 m for each test. All ocular refractions were converted into spherical equivalents (SEs). RESULTS: The objective SE was significantly more negative with Chronos binocular/monocular refraction system under binocular condition (- 4.08 ± 2.76 D) than with the conventional autorefractometer under monocular condition (- 3.85 ± 2.66 D) (P = 0.002). Although, the subjective SE was significantly more negative with Chronos binocular/monocular refraction system under binocular condition (- 3.55 ± 2.67 D) than with the trial-frame in the real space under monocular condition (- 3.33 ± 2.75 D) (P = 0.002), Chronos binocular/monocular refraction system under monocular condition (- 3.17 ± 2.57 D) was not significantly different from that in trial-frame in real space under monocular condition (P = 0.33). CONCLUSION: These findings suggest that the Chronos binocular/monocular refraction system, which can complete both objective and subjective ocular refraction tests in a single unit, is suitable for screening ocular refraction, although it produces slightly more myopic results. Furthermore, subjective ocular refraction testing accuracy in Chronos binocular/monocular refraction system can be equivalent to trial-frame in real-space testing by switching from binocular to monocular condition.

Peripheral Refraction Using Ancillary Retinoscope Component (P-ARC).

Purpose: To assess the agreement of retinoscope-based peripheral refraction techniques with the criterion standard open-field autorefractor. Methods: Fifty young adults (mean age, 24 ± 3 years) participated in this study. Two masked, experienced senior examiners carried out central refraction and peripheral refraction at the temporal 22° (T22°) and nasal 22° (N22°) eccentricities. Peripheral refraction techniques were (a) peripheral refraction using ancillary retinoscope component (P-ARC), (b) retinoscopy with eye rotation, and (c) open-field autorefractor. Peripheral refraction with retinoscopy values was compared with an open-field autorefractor (Shinn Nippon NVision-K) to assess the agreement. All measurements were taken from the right eye under noncycloplegic conditions. Results: The mean difference ±95% limits of agreement of peripheral refraction values obtained using P-ARC from T22° (+0.11 diopters [D] ± 1.20 D; P = 0.20) or N22° (+0.13 D ± 1.16 D; P = 0.13) were comparable with open-field autorefractor. The eye rotation technique compared to autorefractor showed a significant difference for T22° (+0.30 D ± 1.26 D; P = 0.002); however, there was an agreement for N22° (+0.14 D ± 1.16 D; P = 0.10). With respect to the identification of peripheral refraction patterns, examiners were able to identify relative peripheral hyperopia in most of the participants (77%). Conclusions: Peripheral refraction with P-ARC was comparable with open-field autorefractor at T22° and N22° eccentricities. Peripheral retinoscopy techniques can be another approache for estimating and identifying peripheral refraction and its patterns in a regular clinical setting. Translational Relevance: Retinoscope with P-ARC has high potential to guide and enable eye care practitioners to perform peripheral refraction and identify peripheral refraction patterns for effective myopia management.

[Understanding and reflection on the prevention and control of pre-myopia in children].

The International Myopia Institute introduced the concept of "pre-myopia" in 2019, defining it as children with refractive error ≤+0.75 D and >-0.50 D. By considering baseline refractive error, age, and other quantifiable risk factors, there is a significant likelihood that individuals falling into this category may develop myopia in the future. Therefore, it is deemed worthwhile to implement preventative intervention measures.This article delves into the epidemiology of premyopia in children and adolescents, the criteria for determining pre-myopia, the characteristics of refractive changes, and the existing evidence gaps in pre-myopia control technology. Furthermore, it explores the role and advantages of implementing pre-myopia control to enhance efforts in preventing and managing myopia. The paper highlights the essential value and future trajectory of pre-myopia control in the comprehensive management of myopia. The ultimate goal is to foster collaboration with professionals, aiming to discuss innovative strategies for effectively preventing and managing the onset and progression of myopia.

The Freiburg Acuity Test in Preschool Children: Testability, Test-Retest Variability, and Comparison With LEA Symbols.

Purpose: To determine the testability, performance, and test-retest variability (TRV) of visual acuity (VA) assessment using the Freiburg Visual Acuity Test (FrACT) compared to the LEA Symbols Test (LEA) in preschool children. Methods: In 134 preschool children aged 3.0 to 6.8 years, monocular VA of each eye was measured twice with a four-orientation Landolt C version of the FrACT and once with the LEA. FrACT runs were preceded by a binocular run for explanatory purposes. Test order alternated between subjects. Optotypes were presented on a computer monitor (FrACT) or on cards (LEA) at a distance of 3 m. Results: Overall, 68% completed the FrACT (91/134 children) and 88% completed the LEA (118/134 children). Testability depended on age: FrACT, 19% (<4 years) and 87% (≥4 years); LEA, 70% (<4 years) and 95% (≥4 years). Mean ± SD VA difference between tests was 0.11 ± 0.19 logarithm of the minimum angle of resolution [logMAR], with LEA reporting better acuity. The difference depended on age (0.27 ± 0.23 logMAR [<4 years], 0.09 ± 0.18 logMAR [≥4 years], P < 0.001) and on test sequence (higher age dependence of FrACT VAs for LEA first, P < 0.001). The 95% limits of agreement for the FrACT TRV were ±0.298 logMAR. Conclusions: The examiner-independent FrACT, using international reference Landolt C optotypes, can be used to assess VA in preschool children aged ≥4 years, with reliability comparable to other pediatric VA tests. Translational Relevance: Use of the automated FrACT for VA assessment in preschool children may benefit objectivity and validity as it is a computerized test and employs the international reference Landolt C optotype.

Korean version of the MNREAD acuity chart.

To investigate the efficacy of the Korean version of the Minnesota low vision reading chart. A Korean version consisting of 38 items was prepared based on the MNREAD acuity chart developed by the University of Minnesota. A linguist composed the representative sentences, each containing nine words from second and third grade levels of elementary school. Reading ability was measured for 20-35-year-old subjects with normal visual acuity (corrected visual acuity of logMAR 0.0 or better). The maximum reading speed (words per minute [wpm]) for healthy participants, reading acuity (smallest detectable font size), and critical print size (smallest font size without reduction of reading speed) were analyzed. The average age of the subjects was 28.3 ± 2.6 years (male:female ratio, 4:16). The average reading time for 38 sentences was 3.66 ± 0.69 s, with no differences in the average maximum reading speed between sentences (p = 0.836). The maximum reading speed was 174.2 ± 29.3 and 175.4 ± 27.8 in the right and left eye, respectively. Reading acuity was measured as logMAR 0.0 or better in 80% of the cases. All subjects showed a critical print size of 0.2 logMAR or better. The overall reading ability can be measured using the Korean version of the MNREAD acuity chart, thereby making it useful in measuring the reading ability of those with Korean as their native language.

Correlation analysis of angles κ and α with the refraction and anterior segment parameters in children.

AIM: To investigate the correlation of angles α and κ with the refractive and biological parameters in children. METHODS: This case-series study included 438 eyes of 219 children (males/females = 105/114, age: 3-15 years). Ocular biometric parameters, including axial length, corneal radius of curvature (CR), white-to-white distance (WTW), angle κ and angle α, were measured using IOL Master 700; auto-refraction were assessed under cycloplegia. The eyes were assigned to different groups based on CR, WTW, and gender to compare the angles α and κ, and analyze the correlations between the differences of biological parameters on angles α and κ. RESULTS: The means of axial length, CR, WTW, angle α, and angle κ were 23.24 ± 1.14 mm, 7.79 ± 0.27 mm, 11.68 ± 0.41 mm, 0.45 ± 0.25 mm, and 0.27 ± 0.22 mm, respectively. Angle α was correlated with CR and WTW (fixed effect coefficient [FEC] = 0.237, p = 0.015; FEC = -0.109, p = 0.003; respectively), and angle κ also correlated with CR and WTW (FEC = 0.271, p = 0.003; FEC = -0.147, p < 0.001, respectively). Comparing subgroups, the large CR and small WTW group had larger angles α (0.49 ± 0.27 vs. 0.41 ± 0.21, p < 0.001; 0.46 ± 0.27 vs. 0.44 ± 0.21, p < 0.05, respectively) and κ (0.29 ± 0.25 vs. 0.24 ± 0.15, p < 0.01; 0.29 ± 0.25 vs. 0.26 ± 0.19, p < 0.05, respectively). The differences in interocular angles α and κ showed correlation with interocular WTW (r = - 0.255, p < 0.001; r = - 0.385, p < 0.001). Eyes with smaller WTW tended to have larger angle κ (0.28 ± 0.27 vs. 0.25 ± 0.15, p < 0.05). CONCLUSION: The size of angle α/κ may be correlated to CR and WTW, and a larger WTW eye may suggest a smaller angle κ compared with the fellow eye.

Longitudinal Changes in Choroidal Thickness Varied With Refractive Progression in Myopic and Non-Myopic Children: A Two-Year Cohort Study.

Purpose: To evaluate the longitudinal changes in subfoveal choroidal thickness (SFCT) in children with different refractive status. Methods: A total of 2290 children 3 to 14 years old who attended the first year of kindergarten (G0), first year of primary school (G1), fourth year of primary school (G4), or first year of junior high school (G7) in Guangzhou, China, were recruited and followed up for 2 years. All participants received cycloplegic autorefraction, axial length measurement and SFCT measurement using a CIRRUS HD-OCT device. Children were divided into groups of persistent non-myopia (PNM), persistent myopia (PM), or newly developed myopia (NDM). Children in the PNM and PM groups were further divided into subgroups of stable refraction (absolute mean annual spherical equivalent refraction [SER] change < 0.5 D) and refractive progression (absolute mean annual SER change ≥ 0.5 D). Results: The mean ± SD ages for the G1 to G7 cohorts were 3.89 ± 0.30, 6.79 ± 0.47, 9.71 ± 0.34, and 12.54 ± 0.38, years, respectively. SFCT consistently decreased in the NDM group across the G1 to G7 cohorts (all P < 0.001) and exhibited variability across different age cohorts in the PNM and PM groups. Further subgroup analysis revealed significant thickening of SFCT in the PNM-stable group among the G0, G1, and G7 cohorts (all P < 0.05), whereas it remained stable among all cohorts in the PM-stable group (all P > 0.05). Conversely, SFCT exhibited thinning in the G4 and G7 cohorts in the PM-progressive group (both P < 0.01) and for the entire cohort of children in the PNM-progressive group (P = 0.012). Conclusions: SFCT increased in nonmyopic children with stable refraction, remained stable in myopic children maintained stable refraction, and decreased in those with refractive progression, whether they were myopic or not.

Validation of a computerized version of the MNREAD chart for children.

PURPOSE: We aimed the develop and validate a computerized version of the MNREAD for the assessment of reading speed for children. METHODS: A computerized version of the MNREAD was built in Psykinematix software using the same parameters as the physical chart. We measured the reading velocity of 104 children (n = 44 of the 3rd grade; n = 60 of the 5th grade). Bland-Altaman analysis was used to quantify agreement between two chart measurements. RESULTS: Comparison between the 3rd and 5th-grade children for physical and computerized MNREAD versions showed statistical differences in Maximum Reading Speed (F = 2669.6; p < 0.001), Critical Print Size (F = 17.49; p < 0.001), and Reading Acuity (F = 14.19; p = 0.002) with huge effect size (η2 = 0.930). No differences were found between the versions within grades. Bland-Altman analysis showed 95% of the data points within ± 2 s of the mean difference, suggesting a similarity between versions of the MNREAD parameters. CONCLUSION: Our reading speed values for children in the 5th grade were higher than previous studies, suggesting a better quality of the assessment in the computerized version. Tolerance Limits were calculated as normality references for clinical purposes.

Agreement in non-cycloplegic and cycloplegic refraction between a photoscreener and a calibrated autorefractor.

INTRODUCTION: Photoscreeners have been shown to provide excellent measurements of the refractive error. However, whether they could be used for assessing cycloplegic refraction has not been examied. This study aimed to evaluate the agreement between cycloplegic and non-cycloplegic measurements obtained using a photoscreener and stationary autorefractor, respectively. METHODS: This study included all patients undergoing routine ophthalmic examination at the Hygeia Clinic (Poland) from June to July 2022. Each patient underwent non-cycloplegic and cycloplegic refraction assessments using the 2WIN photoscreener (Adaptica SRL, Padova, Italy) and an ARK-1 stationary autorefractor ARK-1 (Nidek Co Ltd., Tokyo, Japan), respectively. Each pair of assessments was conducted in random order, and all values were determined at a vertical distance of 12 mm. The agreement between cycloplegic and non-cycloplegic measurements was assessed using paired t-tests, Bland-Altman and ABCD ellipsoids. RESULTS: This analysis included 82 patients, of which 52 were female. Their mean age was 34.39 ± 13.13 years. The non-cycloplegic spherical equivalent (SE) did not differ significantly between the 2WIN (- 1.22 ± 2.45) and ARK-1 (- 1.19 ± 2.96) devices (p = 0.580). However, the cycloplegic SE values demonstrated more negative values with the 2WIN device (- 1.13 ± 2.19) than with the ARK-1 device (- 0.75 ± 3.03; p = 0.007). The non-cycloplegic and cycloplegic measurements were strongly correlated between the devices (r = 0.9473 and 0.9411, respectively). However, the correlation between their cycloplegic shifts in SE was low (r = 0.2645). Ellipsoid refraction aligned better non-cycloplegic (ARK-1 = 1.00; 2WIN = 1.74) than with cycloplegic refraction (ARK-1 = 1.43; 2WIN = 1.90). CONCLUSION: While the cycloplegic measurements obtained with the 2WIN photoscreener were strongly correlated with those obtained with the ARK-1 stationary autorefractor for most of the analyzed parameters, they should not be considered interchangeable.

Clinical report: Virtual reality enables comparable contrast sensitivity measurements to in-office testing (pilot study).

SIGNIFICANCE: Vision health disparities largely stem from inaccessibility to vision specialists. To improve patient access to vision tests and to expedite clinical workflows, it is important to assess the viability of virtual reality (VR) as a modality for evaluating contrast sensitivity. PURPOSE: This study aimed to assess the validity of a VR version of the Pelli-Robson contrast sensitivity test by comparing its results with those of the corresponding in-office test. METHODS: Twenty-eight participants (mean ± standard deviation age, 37.3 ± 20.5 years) with corrected vision were recruited for testing on a voluntary basis with randomized administration of the in-office test followed by the VR analog or vice versa. Nineteen participants took each test twice to assess test-retest consistency in each modality. Virtual reality tests were conducted on a commercial Pico Neo Eye 2 VR headset, which has a 4K screen resolution. The environment for both tests was controlled by the participant for location and lighting. RESULTS: Similar sensitivity scores were obtained between testing modalities in both the right (n = 28 participants; Wilcoxon match-paired signed rank [SR], p=0.7) and left eyes (n = 28 participants; Wilcoxon match-paired SR, p=0.7). In addition, similar test-retest scores were found for VR (n = 19 participants; Wilcoxon match-paired SR, p=1.0) or in-office (n = 19 participants; Wilcoxon match-paired SR, p=1.0) tests. Virtual reality Pelli-Robson results correlated well with in-office test results in variably diseased participants (n = 14 eyes from 7 participants, R2 = 0.93, p<0.0001). CONCLUSIONS: In this pilot trial, we demonstrated that VR Pelli-Robson measurements of corrected vision align with those of in-office modalities, suggesting that this may be a reliable method of implementing this test in a more interactive and accessible manner.

Could driving help us to "see better"? A comparative assessment of saccadic efficiency, visual speed, and attention.

BACKGROUND: This study aimed at comparing drivers' and non-drivers' results in the Adult Developmental Eye Movement with Distractors test (ADEMd) and the Useful Field of View test (UFOV). METHODS: One hundred and twenty Spaniards (mean age 50.90 ± 17.32 years) without eye disease voluntarily participated in this cross-sectional descriptive study. Participants in a single experimental session completed a questionnaire on sociodemographic, health, eyesight, and driving information. They also performed the ADEMd and UFOV tests randomly following standardized protocols. The ADEMd is a visual-verbal test that measures saccadic efficiency and visual attention. Brown-Forsythe (B-F) tests with Games-Howell post-hoc adjustments were conducted to assess differences between groups. Groups were formed according to sex, age (young adults, adults, and older adults), and driver/non-driver for further analysis. Additionally, associations between dependent variables were assessed through Spearman's correlations. RESULTS: Drivers obtained significantly better results in the ADEMd compared with non-drivers. Non-significant differences between drivers and non-drivers were encountered in the UFOV. Additionally, significant differences were observed between sexes and age groups. It is worth highlighting that non-driver's age significantly correlated with worse ADEMd performance (rho = .637 to .716). This correlation was non-significant in drivers. Similarly, reading hours significantly correlated with better ADEMd performance in non-drivers (rho = - .291 to - .363), but not in drivers. The only significant correlations between ADEMd and UFOV tests were found in drivers (rho = .307 to .410). CONCLUSION: Considering all the discussed results, it could be hypothesized that the driving task promotes abilities, such as oculomotor and cognitive function, which are relevant for the performance in the ADEMd. However, this hypothesis is based on correlational outcomes and further studies should causally assess this possible relation.

SWOT analysis of the models used by social enterprises in scaling effective refractive error coverage to achieve the 2030 in SIGHT in Kenya.

Uncorrected refractive error has predominantly been delivered through commercial entrepreneurship in Kenya. However, to achieve the 2030 IN SIGHT, integration of other forms of entrepreneurship such as the social entrepreneurship is desirable to supplement the efforts of the dominant commercial entrepreneurship. Therefore, this study intended to undertake a SWOT analysis of the current models used by social enterprises in scaling effective refractive error coverage to achieve the 2030 IN SIGHT in Kenya. A review of the seven national strategic plans for eye health in Kenya was undertaken to get a glimpse on the efforts directed towards uncorrected refractive error in achieving the 2030 IN SIGHT. The review was inclined towards assessing the efforts directed by the strategic plans towards scaling human resource, spectacle provision and refraction points. A SWOT analysis was undertaken based on the financial, impact and the approach report for each model. A key informant interview was conducted with a representative and three to five members of the social enterprise about the model. Thereafter, the modified SWOT analysis based on the review and the interview was presented to the representatives of the social enterprises. Purposive sampling was used to identify seven models used by social enterprises in the delivery of refractive error services in Kenya. Finally, the recommendations were presented to key opinion leaders for an input through a Delphi technique. Out of the seven national strategic plans for eye health reviewed, only the strategic plan 2020-2025 intends to establish optical units within 15 different counties in Kenya. Of the seven models currently utilized by social enterprises, only the Kenya Society for the Blind has integrated the telemedicine concept. On application of mHealth, all of the social enterprises models tend to embrace the approach for screening activities. None of the models has a strengthened referral pathway utilizing telereferral and telemedicine. Out of all the models, only Operation Eyesight Universal, Fred Hollow Foundation and Peek Acuity do not depend on sales of subsidized spectacles for sustainability. Every model has the capacity to propel the delivery of refractive error services depending on its comprehensiveness. However, for the 2030 IN SIGHT to be achieved, models prioritizing human resource through telemedicine integration, service provision across all sectors, awareness creation and enhancing cost efficiency are desirable.

The effect of multifocal contact lenses on the dynamic accommodation step response.

PURPOSE: To measure the dynamic accommodation response (AR) to step stimuli with and without multifocal contact lenses (MFCLs), in emmetropes and myopes. METHODS: Twenty-two adult subjects viewed alternating distance (0.25D) and near (3D) Maltese crosses placed in free space, through two contact lens types: single vision (SVCL) or centre-distance multifocal (MFCL; +2.50D add). The AR level was measured along with near to far (N-F) and far to near (F-N) step response characteristics: percentage of correct responses, magnitude, latency, peak velocity and duration of step response. RESULTS: There was no difference between N-F and F-N responses, or between refractive groups in any aspect of the accommodation step response dynamics. The percentage of correct responses was unaffected by contact lens type. Through MFCLs, subjects demonstrated smaller magnitude, longer latency, shorter duration and slower peak velocity steps than through SVCLs. When viewing the near target, the AR through MFCLs was significantly lower than through SVCLs. When viewing the distance target with the MFCL, the focal points from rays travelling through the distance and near zones were approximately 0.004D behind and 2.50D in front of the retina, respectively. When viewing the near target, the respective values were approximately 1.89D behind and 0.61D in front of the retina. CONCLUSION: The defocus error required for accommodation control appears not to be solely derived from the distance zone of the MFCL. This results in reduced performance in response to abruptly changing vergence stimuli; however, these errors were small and unlikely to impact everyday visual tasks. There was a decrease in ocular accommodation during near tasks, which has previously been correlated with a reduced myopic treatment response through these lenses. With MFCLs, the estimated dioptric myopic defocus was the largest when viewing a distant stimulus, supporting the hypothesis that the outdoors provides a beneficial visual environment to reduce myopia progression.

Evaluation of contrast sensitivity in visually impaired individuals using K-CS test. A novel smartphone-based contrast sensitivity test-Design and validation.

BACKGROUND: To describe the development and investigate the accuracy of a novel smartphone-based Contrast Sensitivity (CS) application, the K-CS test. METHODS: A total of 67 visually impaired and 50 normal participants were examined monocularly using the novel digital K-CS test and the Pelli-Robson (PR) chart. The K-CS test examines letter contrast sensitivity in logarithmic units, using eight levels of contrast from logCS = ~0,1 to logCS = ~2,1 at two spatial frequencies of 1.5 and 3 cycles per degree (cpd). The K-CS test was compared to the gold standard, PR test and intra-session test repeatability was also examined. RESULTS: The K-CS test in normally sighted was found to agree well with the PR, providing comparable mean scores in logCS (±SD) (K-CS = 1.908 ± 0.06 versus PR = 1.93 ± 0.05) at 1.5 cpd and mean (± SD) logCS at 3 cpd (K-CS = 1.83 ± 0.13 versus PR = 1.86 ± 0.07). The mean best corrected visual acuity of visually impaired participants was 0.67 LogMAR (SD = 0.21) and the K-CS was also found to agree well with the Pelli-Robson in this group, with an equivalent mean (±SD) logCS at 1.5 cpd: (K-CS = 1.19 ± 0.27, PR = 1.15 ± 0.31), 3 cpd: K-CS = 1.01 ± 0.33, PR = 0.94 ± 0.34. Regarding the intra-session test repeatability, both the K-CS test and the PR test showed good repeatability in terms of the 95% limits of agreement (LoA): K-CS = ±0.112 at 1.5 cpd and ±0.133 at 3 cpd, PR = ±0.143 at 1.5 cpd and ±0.183 in 3 cpd in visually impaired individuals. CONCLUSION: The K-CS test provides a quick assessment of the CS both in normally sighted and visually impaired individuals. The K-CS could serve as an alternative tool to assess contrast sensitivity function using a smartphone and provides results that agree well with the commonly used PR test.

Subjective versus objective refraction in healthy young adults.

PURPOSE: To evaluate objective and subjective refraction differences in healthy young adults. METHODS: Data concerning candidates for the Israeli Air Force Flight Academy, as well as active air force pilots in all stages of service who underwent a routine health checkup between the years 2018 and 2019 were retrospectively analyzed. Objective refraction measured using a single autorefractometer was compared with subjective refraction measured by an experienced military optometrist during the same visit. The results were converted to power vectors (spherical equivalent [SE], J0, and J45). To interpret astigmatism using power vector values, the cylinder power (Cp) was determined. RESULTS: This study included 1,395 young adult participants. The average age was 22.17 years (range, 17-39, 84.8% males). The average SE was - 0.65 ± 1.19 diopter (D) compared with - 0.71 ± 0.91D in the auto- and subjective refraction, respectively (p = 0.001). Cp was 0.91 ± 0.52D and 0.67 ± 0.40D, respectively (p < 0.001). This difference was more common in older participants (p < 0.001). J0 and J45 value differences were not significant. The absolute SE value of subjective refraction was lower in the myopic (p < 0.001) and hyperopic (p < 0.001) patients. CONCLUSIONS: Young hyperopic participants tended to prefer "less plus" in subjective refraction compared with autorefraction. Young myopic participants tended to prefer "less minus" in subjective refraction compared with autorefraction. All participants, but mainly older participants, preferred slightly "less Cp" than that measured using autorefraction; The astigmatic axis did not differ significantly between the methods.

Digital device viewing behaviour in children.

INTRODUCTION: Habitual viewing behaviour is widely believed to be an important contributing factor to the onset and progression of myopia and may be task dependent. The purpose of this study was to quantify the habitual viewing distance of children performing five different tasks on a smartphone digital device. METHODS: The real-time viewing distance in 38 children with their habitual correction was measured using software (MyopiaApp) on a handheld (Google Pixel 3) device. Five tasks were performed in a randomised sequence: playing a game, watching video in a light (680 lux) and dark (5.5 lux) environment and reading small (8 pt) and large (16 pt) text. ANCOVA statistical analysis was used to evaluate the effect of task, group (myope vs. non-myope) and arm length on the median relative viewing distance. RESULTS: Arm length was not correlated with viewing distance in any of the tasks, and there was no significant difference in viewing distance between any of the tasks. Specifically, a two-way mixed ANCOVA indicated that task, refractive group (myopic vs. non-myopic), age and arm length, as well as all two-way interactions were not significantly associated with viewing distance. Overall, 60% of the total variance in viewing distance was accounted for by individual differences. CONCLUSIONS: The average handheld viewing distance was similar across a variety of everyday tasks in a representative sample of myopic and emmetropic children. Neither arm length, age nor refractive group were associated with viewing distance in any of the tasks. Importantly, myopic children of a given size did not hold the smartphone digital device at a different distance for any task than their equally sized non-myopic peers. However, both groups exhibited high inter-individual variability in mean viewing distance, indicating some subjects performed all tasks at further distances while other subjects used at nearer distances.

Parkinson's Disease and Driving Fitness: A Systematic Review of the Existing Guidelines.

BACKGROUND: Motor/nonmotor symptomatology and antiparkinsonian drugs deteriorate the driving ability of Parkinson's disease (PD) patients. OBJECTIVES: Treating neurologists are frequently asked to evaluate driving fitness of their patients and provide evidence-based consultation. Although several guidelines have been published, the exact procedure along with the neurologist's role in this procedure remains obscure. METHODS: We systematically reviewed the existing guidelines, regarding driving fitness evaluation of PD patients. We searched MEDLINE and Google Scholar and identified 109 articles. After specified inclusion criteria were applied, 15 articles were included (nine national guidelines, five recommendation papers, and one consensus statement). RESULTS: The treating physician is proposed as the initial evaluator in 8 of 15 articles (neurologist in 2 articles) and may refer patients for a second-line evaluation. The evaluation should include motor, cognitive, and visual assessment (proposed in 15, 13, and 8 articles, respectively). Specific motor tests are proposed in eight articles (cutoff values in four), whereas specific neuropsychological and visual tests are proposed in seven articles each (cutoff values in four and three articles, respectively). Conditional licenses are proposed in 11 of 15 articles, to facilitate driving for PD patients. We summarized our findings on a graphic of the procedure for driving fitness evaluation of PD patients. CONCLUSIONS: Neurological aspects of driving fitness evaluation of PD patients are recognized in most of the guidelines. Motor, neuropsychological, visual, and sleep assessment and medication review are key components. Clear-cut instructions regarding motor, neuropsychological, and visual tests and relative cutoff values are lacking. Conditional licenses and periodical reevaluation of driving fitness are important safety measures.

Comparison of HOTV optotypes and Lea Symbols: a systematic review and meta-analysis.

PURPOSE: To report the findings of our systematic review and meta-analysis comparing the completion time and testing time of visual acuity testing using Lea Symbols or HOTV optotypes. METHODS: A systematic search of PubMed, SCOPUS, and CINAHL was conducted according to the PRISMA guidelines. RESULTS: The completion rate for HOTV optotypes and Lea Symbols visual acuity testing was reported for 7,948 patients (average age, 3.59 years; age range, 2-17; 49.96% females). The 3-year-olds' completion rate of HOTV was 74.09% (47.93%-93.29%), compared with a Lea Symbols completion rate of 77.80% (53.93%-94.57%). The 4-year-olds' completion rate was 88.20% (63.48%-99.73%) for HOTV and 90.118% (67.42%-99.90%) for Lea Symbols. In 3-year-olds, the mean testing time was 118.33 ± 6.54 seconds for HOTV and 120.33 ± 6.53 seconds for Lea Symbols (P < 0.0001). The difference in testing times in the 4-year-old age group was also statistically significant (86.98 ± 6.12 seconds for HOTV and 94.32 ± 6.57 seconds for Lea symbols) (P < 0.0001). CONCLUSIONS: There was a statistically significant difference in the testing times between the HOTV optotypes and Lea Symbols in both the 3- and 4-year-old age groups; however, the difference of 2-7 seconds on average is unlikely to be clinically significant. Testing speed and completion rate improve with age for both tests.